Threading die



vAug. 13, 1929.

G. M. MEI- IL THREADING DIE Filed April 25. 1927 Patented Aug. 13, 1929.

UNITED STATES GEORGE M. Munn, on nain, PnnNsYLvANra, -Assaefnon 'ro wratni'ains Toor coRPonA'iron, or ERIE, PENNsYLvANiA.

THnEAnING Dru.

Application led April 25,

My invention pertains to threading dies and particularly to that type adapted for the of pipe, for instance from 2 inches to 8 inches. j

By my invention, l have eliminated this difficulty and provided a Chaser bit or die which may be securely clamped withinxthe holder but which is adjustable in said holder whereby the same set of dies may be made f to accommodate and to thread pipe of various diameters, always with suilicent clearance. In other words1 through my invention I have made it possible to thread pipe of 2 inches in diameter or 8 inches in diameter with a single set of dies.

The primary object of my invention is to provide a die or chaser bit formed from a circular piece of material, such as a steel bar, laterally across one side of which the cutting teeth are provided. By the use of` such a round die, a natural clearance is provided for both large and small pipe, made available by a slight adjustment of the round die within the holder. j

A further object is to provide novel means for clamping or holding such a die within the holder.

A still further object is to provide a novel means for adjusting the position of the die within the holder with respect to the cutting point in order to provide adequate clearanceA for the different sizes of pipe.

Other objects and advantages in details of construction and operation will be apparent as the description proceeds, reference now i being had to the igures of the drawing wherein like reference numerals indicate like parts,

Figure l is a side view of the die holder within which my improved die is secured. Figure 2 is a front view of the same. Figure 3 is a detail perspective of my improved chaser bit of die.

i927. serial No. 186,388.

Figure l is a detail cross sectiony illustrat-y ing the adjusting means crossing between the die land die holder. f `y Figure 5 is a detail cross section taken 'on the line 5 5 of Figure le The reference numeral l refers to a 'die holder of the usual type provided with an opening 2 for the reception of the usual headed stud (not shown)k which engages with the cam plate for adjusting the position of the 4die holders radially within the head.

rlfhe lower end of theholder is provided with a circular recess 3 extending substaii` tially through the width of the holder to receive the circular die or c haser bit 4,'th'e outer end of which lies flush with the surface of the holder. An arcuate slot 5 is provided in the holder ertending from the surface thereof rearwardly to a point adjacent Athev end of lthe opening 3 in which the dief'tfis seated. A socket headed clainpingfsc'rew 56 extends into the die holder at right angles to, the slot 5, passing through the same and po-v sitioned directly above the opening 3 whereby that portion ofthe holder on either side of the slot 5 may be clamped tightly about the died. A recess 7 is provided in the side wall of the die holder to receive the socket head of lthe clamping screw 6, whereby suchv head lies iiush with or below the surface of the holder. It will be understood, of course, that by inserting a socketwrench into the head of the screw Y6, the same may be adjusted to tighten or `loosen the clamp'in-glportion of the die holder on either side of the slot 5, whereby the die 4 will be securely held in position or may be rotatednforl adjustment or withdrawn longitudinally Afrom the holder.

The die 4L is provided `-at one end with a recess 8 adapted to receive a pin 9 rigid with the die holder at the inner end of the recess or opening 3 and projecting into such opening to receive the recess 8 in the die when said die is placed in the holder. The recess 8 is slightly larger than the pin 9 whereby msv a slight'rotary adjustment of the die within' such dies is suiicient for pipe ranging trom 2 inches in diameter to 8 inches in diameter. The di'erence in size between the pin 9 and recess 8 has been exaggerated in the drawing for clearness. But assuming that it is of the proper relative size, it will be understood that upon adjusting the die tothe positionv shown in Figure 5, the clearance atlorded with such die will be sutiicient for the threading of pipe from 4 inches to 8 inches in diameter,'and that adjustment oit'V the die to the right in Figure 5 so as that the pin 9 engages With the opposite wall of the recess 8, will permit proper clearance orthe threadingI` of pipe from 2 inches to 4f. inches in diameter.

Recesses 10 are provided in the opposite end of the die to receive a spanner wrench or other instrument by means of which the die may be rotated within the holder, after the screw 6 has been loosened. It will be understood, of course, vthat other suitable means may be provided for this adjustment if desired.

The die is provided on one side thereof with a recess 11, against the vertical wall of which, a threaded pin 12, extending inwardly through the die holder at right angles to said recess 11, is adapted to engage, and which provides a means for a very fine adjustment 'of the die within the holder, and for taking the strain and thrust of the die during the threading operation. This screw pin l2 is also provided with a socket head lying flush or below the surface of the die holder.

A portion of the periphery ot the circular die 4 is provided with teeth 13 cut laterally thereon and that portion of the die lying directly in front of the teeth 13 is cut away as at 14 to provide ample space for the discharge of the cuttings during the threading operation.

It will be clear, of course, that the points of the teeth 13 may be sharpened' and ground backas becomes necessary due to wear, and if necessary after such grinding, the die may be adjusted slightly by means of the screw 12 to bring the cutting edge into proper cutting position.

' The teeth 13 are preferably cut in the die on a conve); radius as shown in dotted lines at 14 and 15 in Figure 1. This permits the presentation of the teeth to the work at the proper angle for most efiicientcutting.

0f course, changes may be made by way of detail without departing from the spirit and scope of this invention. l do not limit myself therefore to the exact structure shown and described other than by the appended claims. f

I claim 1. ln combination, a die holder having a circular recess, a circular threading die therein2 means for rotatably adjusting said die in said recess, means for clamping said die in adjusted position, and means in said recess limiting the adjustment of said die in each direction. j

2. ln combination, a die hoider having a circular recess, a circular threading die therein, means for rotatably adjusting said die in said recess, means if'or clamping said die in adjusted position, and means in said recess limiting the adjustment or" said die in each direction, said limiting means comprising a pin carried by said holder and engaging a recess in said die.

3. 1n combination, a die holder having a .circular recess, a circular threading die therein, a fixed pin projecting into said recess, an opening in said die for receiving said pin and being slightly larger than said pin whereby said die may be rotatably adjusted in said recess, means for adjusting said die and means for clamping said die in adjusted position.

4E. In combination, a die holder having a clamping portion, a circular threading die therein, means for permitting a limited rotatable adjustment of said die in said portion comprising a pin and recess connection between said die and holder, and means for clamping said die in adjusted position.

GEORGE M. Marin 

